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Molecular Weight Calculator

Compute molecular weight (molar mass) from chemical formulas with elemental mass percentages, atom counts, and IUPAC standard atomic weights.

Popular Presets:

💡 Tips: Formula is case-sensitive! Use capital letters for element starts (e.g., NaCl not nacl, Ca not ca). Parentheses () and hydrate dots * or . are fully supported.

Total Molecular Weight (Molar Mass)

180.156 g/mol

C6H12O6 • 24 Total Atoms • 180.156 Da
Total Atom Count 24 atoms
Unique Elements 3 elements
Primary Mass Element Oxygen (53.28%)

Elemental Mass Percentage Breakdown

Element Symbol Atoms Atomic Wt. Mass (g/mol) Mass %
Oxygen O 6 15.999 95.994
53.28%
Carbon C 6 12.011 72.066
40%
Hydrogen H 12 1.008 12.096
6.71%

Understanding your calculation

Method, example and limitations

How the calculation works

Formula mass adds atomic masses multiplied by the number of each atom in the chemical formula. Parentheses multiply the atoms inside the group.

Example to check

Water has two hydrogen atoms and one oxygen atom, giving an approximate molar mass of 18.015 g/mol with commonly used atomic weights.

Before using the result

Isotopic composition and rounding affect precision. Chemical formula parsing does not determine purity, hydration state or whether a substance is safe to handle.

Calculation methodology · Report a result that needs review